Good reviews sell books. The more reviews you have the better you will look to the reader. You also want enough reviews so that you look legitimate and that not just your friends and family posted reviews. You can ask all your friends to post reviews but if Amazon finds that they are “friends”, Amazon may take down the reviews anyway.
A good way to get reviews is to reach out to other authors (check out their websites, find them on social media, look for Facebook Fanpage Exchanges). They may be more sympathetic to your plight and you may want to exchange reviews for each other. Join writing groups that help one another out.
It can also be very disheartening when you repeatedly ask a friend to post a review and they keep forgetting or when a stranger blasts your book. Anyone can be anonymous behind a keyboard so don’t take it to heart, but remember reviews are all part of the business of being an author!